With goalie Henrik Lundqvist pulled for an extra attacker, Washington's Joel Ward took a four-minute penalty for high-sticking Carl Hagelin with 21.3 seconds left in the third period. Richards tied it on the first half of the power play with just 7.6 seconds to go, and Staal won it with a drive that appeared to deflect off a Washington player before beating goalie Braden Holtby.

The top-seeded Rangers can advance to the Eastern Conference finals Wednesday in Washington. If necessary, Game 7 would be back in New York on Saturday.

With the crowd still buzzing over the shocking tying goal, a din that held up through the long intermission, John Mitchell won a faceoff in the Capitals' end to start the winning play. Staal corralled the puck at the right point, glided to the centre of the zone, and fired the drive that set off a wild celebration on the ice and in the seats at Madison Square Garden.

The Rangers mobbed each other at centre ice as the crushed Capitals trudged toward the tunnel to their dressing room. Then, the New York players raised their sticks to the crowd as red, white and blue streamers cascaded down from the rooftop.

The celebration, that culminated in fireworks as the three stars of the game were announced to the crowd, seemed almost inevitable after Richards tied it.

After no success with traditional 5-on-4 power plays, the Rangers made the most of their 6-on-4 edge as Lundqvist watched from the bench.

Michael Del Zotto took a shot that hit traffic in front to the right of Holtby. Ryan Callahan took two or three hard whacks at the loose puck, but couldn't get it forward. Richards jammed his stick into the maze of legs and poked the puck past Holtby just before he was able to cover it with his glove.

John Carlson, who had given the Capitals a 2-1 lead in the third period, couldn't keep the puck out, either, after he got in behind Holtby as a last line of defence.

Anton Stralman staked the Rangers to a 1-0 lead during a dominant first period for New York, but Brooks Laich answered for the Capitals in the second.

Carlson then snapped the 1-1 tie 4:20 into the third with the goal that appeared to put the seventh-seeded Capitals on the brink of knocking out the top-seeded Rangers.

It would have marked the second straight game that Washington used a man-advantage goal from a defenceman to earn a victory, but instead the Rangers won their second of the series in overtime.

The Capitals, 0-5 in the playoffs when their opponent scores first, were fortunate to even be in position to win as they were outshot 38-18 overall by the Rangers.

Washington woke up a bit in the second period and got even, despite recording only six shots on Lundqvist. However, that was two more than the Capitals generated in the first.

The Rangers held a 26-10 edge in shots in the first 40 minutes, but had only a 1-1 tie to show for it heading into the tense third period.

The Capitals tied it in the second after gaining control of the puck following a faceoff in the Rangers' end. Alex Ovechkin, who heard even more boos than usual from the Garden crowd, sent a pass from the side boards to the right of Lundqvist that bounced off Rangers forward Brian Boyle. The puck came right to Laich in the slot for a hard drive that beat Lundqvist inside the right post to make it 1-1 at 8:15.

New York had numerous chances to extend its lead or get back in front before Washington tied it, but the Rangers' power play continued to struggle and looked disorganized. In three advantages over the first two periods, the Rangers failed to even record a shot on Holtby, who appeared to gain more confidence and stability as the game went on.

The Rangers had been 2 for 16 on the power play in the series before Ward's penalty changed everything.

After a first period in which Washington blocked nine shots, the Capitals got in front of eight more in the second and allowed only nine to get through to Holtby. The Rangers, who trail only Washington in blocked shots in these playoffs, had six through two periods and yielded 10 on goal.

The Rangers came out fast and showed the urgency they claimed they needed in the first period and outshot the Capitals 17-4 ????????? a far cry from the 14-3 edge Washington held through 20 minutes on Saturday.

The shots were already one-sided when Stralman fired one in from a bad angle that beat the shaky-looking Holtby between the pads. Stralman skated in from the right point, went around forward Matt Hendricks, who had dropped to the ice to attempt to block a shot that never came, and finally let a drive go from the bottom edge of the right circle to make it 1-0 at 10:44.

New York's 17 shots were the most by either team in a period during this series, three shy of the Rangers' total in their 3-2 loss in Game 4, and three more than they had in winning Game 1.

The Rangers also came out hitting, connecting throughout the period that featured crushing blows by Callahan and Del Zotto. Washington had set the physical tone just 8 seconds in when Troy Brouwer levelled Ryan McDonagh behind the New York net.

Notes: Stralman scored his first two career NHL playoff goals ????????? both on the power play ????????? in the Rangers' first-round series win over Ottawa. ... Washington is 6-1 in the playoffs when it scores first. ... The Capitals are 3 for 16 on the power play in the series. ... The Rangers won Game 3 in triple overtime 2-1.